Efficient telecommunications systems require an ability to provide users with telephone or directory numbers of subscribers in response to telephonic requests. Generally such information is obtained by dialing a directory assistance number (411) which results in connection to a directory assistance office which supplies the telephone number in response to a customer request for residence, business or government listing.
Many present day directory assistance systems use a computer-aided search arrangement. In such a system a customer places a call to an operator and gives the particulars of a request for a directory listing. The operator keys identifying data into a computer for locating directory listings. When the operator has found an apparently correct listing in a computer generated display the operator signals the identity of the correct listing in the display and disconnects from the directory assistance call. The listing is then automatically announced to the calling telephone customer.
Daudelin U.S. Pat. No. 4,797,910 issued Jan. 10, 1989 describes a proposal which is said to further reduce operator work time.
More recently there have been numerous proposals for effecting a greater degree of automation. An early example of such a proposed system is described in Byram et al. U.S. Pat. No. 3,928,724 issued Dec. 23, 1975.
The Byram et al. patent describes a voice actuated directory assistance system in which the user spells the last name of the subscriber whose telephone number is desired. The user dials the uniform directory assistance number (411), causing the telephone switching system to connect the telephone to an audio-digital interface system and causing a first prestored prompt to be provided to the user from system memory. This message instructs the user to spell letter-by-letter the last name of the subscriber whose telephone number is desired. Each time a letter of the subscriber's last name is spelled it is encoded into digital form and stored in a register. The computer compares the stored digital signals with the digital signals representing subscribers stored in its main memory, and each time there is a match causes the identification and telephone number of the subscriber to be stored in a first temporary memory and the number of such matches in reading through the entire main memory to be stored in a match counter.
A selected one of three recorded messages is then transmitted to the user with the selected message corresponding to one of four different situations. These situations are (1) one exact match between the user provided input and the stored addresses from the main memory of the computer; (2) no match; (3) more than one match and (4) one or more partial matches. If only one subscriber is found corresponding to the spelling of the last name the telephone number is provided by the computer to the audio-digital interface system which converts the digital signal received from the computer into an audio signal and transmits the audio signal to the telephone receiver held by the user. If no subscriber corresponding to the spelling of the name is found the user is so informed and asked to provide alternate spellings or to hang up the receiver.
Padden et al. U.S. Pat. No. 4,979,206 issued Dec. 18, 1990, describes an arrangement intended to minimize the speech recognition requirement. Thus this patent describes an arrangement relying upon alphabet and numbers only, i.e., zip code location and name and address spelling. Two embodiments are disclosed. In one embodiment the caller dials the regular directory assistance number such as 411 or 555-1212. The system then proceeds with the prompt and response dialogue until a directory number is located in the database. At this point the located number is orally delivered to the user. This methodology is illustrated in the flow charts of FIGS. 2-6 under the "Detect Regular DA Number" option referenced by the numeral 150 in FIG. 2.
The alternative embodiment involves a situation in which the caller desires the system to automatically complete the call. In this case the caller dials a special directory assistance code such as 311 or 555-1234. The system then proceeds through the same methodology with the added feature of call completion. This methodology is also illustrated in FIGS. 2-6 under the "Detect Special DA Number" referenced at 101.
U.S. Pat. No. 5,052,038 issued Sep. 24, 1991, describes a directory assistance request processor wherein the name of the subscriber whose telephone number is sought is entered through the use of standard DTMF push buttons using the grouped alphabetic designators on those buttons.
Carter et al. U.S. Pat. No. 4,608,460, issued Aug. 26, 1986, describes an automatic directory assistance apparatus and method which uses automated voice prompts to a caller in order to obtain an input identifying the called party. The user responds by utilizing DTMF signal inputs representing the first four letters of the last name and the initial of the first name of the desired party.
Dubnowski et al. U.S. Pat. No. 4,164,025 issued Aug. 7, 1979, describes an arrangement for recognizing words corresponding to a sequence of spelled input character signals.
The use of automated speech recognition devices to process spoken information received over telephone lines is well known and is becoming increasingly popular. If such automated speech recognition equipment is utilized it is important that the speaker communicate accurate information to the system with maximum machine assistance and minimum user inconvenience. For example it is desirable that the caller be prompted as few times as possible to repeat questionable information or to supply additional information to permit reaching a solution to the selection process.
Accordingly it is an object of this invention to provide automated directory assistance in a manner which is not only efficient but also acceptable and pleasing to the user.
It is another object of the invention to provide automated directory assistance using available speech recognition equipment in a unique manner to attain an improved level of effectiveness.
It is another object of the invention to provide automated directory assistance using available speech recognition devices in an improved manner to minimize the necessity to rely on operator intervention.
It is another object of the invention to provide automated directory assistance using multiple types of available speech recognition equipment to maximize the successful provision of the requested assistance without reliance upon operator intervention.
These and other objects and advantages of the invention will become more apparent upon reference to the following specification, drawings and claims.